Adele Ballantyne copied details from patient credit cards and files and passed them on to her stepfather, John Hill.
Hill was jailed for two years for his part in the scheme which involved him ordering goods using the details and selling them on, Glasgow Sheriff Court heard.
Their co-accused, Patrice Massey, was ordered to carry out 300 hours' community service for receiving delivery of the goods - mainly industrial catering equipment - at her home in Clydebank.
Sentencing Adele Ballantyne, Sheriff Robert Anthony told her: "You blatantly abused a position of trust and as such the only means of disposal is a term of imprisonment."
At an earlier hearing, Ballantyne, 22, of Earl Street, Scotstoun, admitted copying credit and debit card details while employed at the Dental Practices, Gardner Street, Glasgow, and Victoria Road, Glasgow, between August 28, 2006, and November 29, 2006.
Hill, 32, also of Earl Street, Scotstoun, pled guilty to using the details to order goods over the telephone.
Massey, 20, of Jean Armour Drive, Clydebank, admitted receiving the goods worth £18,599.62. She was paid just £100 for each delivery she received, totalling £1100.
They were originally charged with defrauding £58,979.84 but the Crown accepted their pleas of guilty to the lesser amount.
Prosecutor Aileen Thom told the court that Adele Ballantyne had worked at the surgery for 18 months before she started stealing the patients' details.
Miss Thom said: "A gross breach of trust has occurred due to the way dental patients' debit and credit cards were used and all were unaware of what had occurred until they received in statements details of items they had not bought."
Hill's defence lawyer William McIntyre and Ballantyne's lawyer Patrick Campbell both told the court their clients carried out the offenses because they were struggling financially and had been threatened with eviction.
Massey's lawyer, Tony Mahon, said she was a "small cog in the machine."